1. FIELD OF THE INVENTION
This invention relates generally to computer networks and, more particularly, to an improved system and method of constructing data packets for transmission between computers in a system of computer networks.
2. BACKGROUND OF THE INVENTION
A computer network includes multiple computers connected with a physical medium, such as a cable. Data sent from a source computer to a destination computer may be lost or changed because of congestion or noise in the network. Schemes exist to transmit data using a protocol that is xe2x80x9creliable,xe2x80x9d meaning that the protocol guarantees accurate delivery of transmitted data. Operating a reliable communication protocol, however, has entailed substantial overhead in the network computers.
More particularly, approaches exist for improving the performance of a computer""s implementation of a reliable communication protocol. For example, a technique exists for performing one aspect of a common protocol suite (TCP/IP) in hardware. Request for Comment (RFC) 1936, xe2x80x9cImplementing the Internet Checksum in Hardware,xe2x80x9d describes a technique for performing a calculation in hardware that is required by various communication protocols.
In addition, approaches exist which combine the calculations described above with additional hardware to efficiently handle interrupts. One such approach, described in the white paper, xe2x80x9cNext Generation Adapter Design and Optimization for Gigabit Ethernetxe2x80x9d by Alteon Networks, involves handling multiple communication protocol interrupts in hardware. This alleviates the need for the main computer processor to handle multiple interrupts.
It is an object of the present invention to provide an improved method and apparatus for efficiently operating a reliable communication protocol in a computer network. In particular, the present invention provides an improved method and apparatus for constructing a portion of an acknowledgement signal to be sent upon successful receipt of an incoming signal.
In accordance with the preferred embodiment of the present invention, a protocol processing subsystem receives data from another computer in a computer network. Upon successful receipt of the data, the protocol calls for construction of an acknowledgement signal to be sent from the receiving computer to the sending computer. The protocol processing subsystem of the present invention automatically constructs this acknowledgement signal. In the preferred embodiment, the construction of this acknowledgement signal occurs in hardware which alleviates the need for the protocol processing software to construct the acknowledgement signal. This results in a significant improvement in system performance over systems according to the prior art.